This invention relates to a proportioner, particularly to a proportioner for mixing a concentrate with a diluent and delivering the proportioned admixture to a utilization system.
Manufacturing procedures often require the mixing of a concentrate with a liquid such as water to form an admixture which is used in the manufacturing processes. One example of a system using this type of procedure is a die lubricating system in which die lubricant is delivered from a central system to individual die casting machines. The die lubricant is delivered to the manufacturing plant in concentrate form and is diluted on site in a desired proportion with a diluent such as water or other liquid. The dilution is delivered through an in-plant delivery system to the individual machines.
One advantage of course in shipping concentrate and diluting it on site is that shipping costs are considerably lower. It is however necessary for the plant to have apparatus for mixing the concentrate in a desired proportion with diluent. It is also important that the concentrate be accurately proportioned with the diluent.
U.S. Pat. No. 4,186,769, issued Feb. 5, 1980, commonly assigned, relates to a liquid mixing and delivering apparatus which is of this general type. In the apparatus disclosed in that patent the concentrate and diluent are mixed in proportion by metering pumps, and the admixture is accumulated in an accumulator. Control of metering pump speeds is intended to yield the desired proportioning. The concentration may be varied by speed adjustments.
U.S. Pat. No. 3,799,402 also relates to an apparatus for preparing an admixture by dilution of a concentrate. This type of a system may be considered as a double acting piston type system having one double acting piston for metering the diluent, i.e. the water, and a second double acting piston for the concentrate. The pistons' sizes and strokes determine the proportioning.
The present invention is directed to a new and improved proportioner of the type for preparing an admixture by the dilution of a concentrate. The present invention offers a number of advantages including the following: relatively high flow rates for delivery; no pressure limitations on delivery except those which are imposed by the equipment used; a limited number of moving parts; accumulation of a limited quantity of admixture while assuring the availability of supply for all demands for which the system is designed.
Briefly, the present invention in its preferred embodiment as disclosed in this application comprises a pair of accumulators which are alternately repetitively recharged so that one of the two accumulators is always on-line for delivery of admixture to the utilization system and during the time that one of the two accumulators is online, the other accumulator is recharged. Each accumulator can be rapidly recharged in accurate proportion before the contents of the other accumulator have been exhausted. Hence, continuous availability of admixture is assured, but with only a limited accumulation of admixture at any given time.
The invention also comprises a means for conveniently adjusting the amount of concentrate which is introduced into each recharging of an accumulator so that an accurate proportion of concentrate is assured for a given volume of diluent. The volume of diluent is determined by the size of an accumulator and the proportion is set by appropriate adjustment of the amount of concentrate delivered per each recharging of an accumulator. The concentrate is delivered to an accumulator by means of a piston in which the piston is precharged with a given volume of concentrate prior to the recharging of an accumulator. When an accumulator is to be recharged, the piston is operated to force the concentrate into the accumulator and at the same time the diluent is introduced by merely opening a valve and allowing the diluent to flow into the accumulator. Hence, it is unnecessary to meter the amount of diluent since the amount of diluent will be determined by the volume of the accumulator. In this regard the valve is shut off when the accumulator has been filled to a desired fill level as sensed by a level switch.
Associated with the concentrate delivery piston is a stroke adjusting mechanism which provides an effective means for adjusting the piston stroke and hence the volume of concentrate per recharging of an accumulator. The mechanism may be conveniently adjusted manually by means of a rotary handle.
An electrical circuit is associated with the system to produce the desired operating sequence of its various component parts. The electrical circuit contains interlocking features to assure the desired sequence of operation and to warn against the occurrence of undesired activities.
The foregoing features, advantages and benefits of the invention, along with additional ones, will be seen in the ensuing description and claims which should be considered in conjunction with the accompanying drawings. The drawings disclose a preferred embodiment of the invention according to the best mode contemplated at the present time in carrying out the invention.